We begin with the growing Republican criticism of the Russia investigation and calls for outright purge at one of the nation's intel agencies. Congressman Francis Rooney, a Florida Republican, says he wants to see the FBI and the Justice Department remove agents with political bias. This after the political views of a few FBI employees were recently revealed in the form of text messages. He went on to call the Russia probe off the rails and the work of the deep state.

Moments ago here on CNN, Congressman Rooney doubled down on his words during an interview with my colleague Brianna Keilar. Watch this.

(BEGIN VIDEO CLIP)

BRIANNA KEILAR, CNN HOST: Are you sure you want to be throwing a word like purge around?

REP. FRANCIS ROONEY (R), FLORIDA: Well, it might be a pretty strong word. I'm not maybe the most nuanced political person in the world coming from a career in business. But I'm pretty frustrated that all the things that have come out by the Strzok and Ohr, and what may or may not have taken place in Deputy General McCabe --

KEILAR: Let me stop you there. Mueller removed Strzok. Ohr was demoted. I mean, so what's the evidence? What's the evidence, then, the biases impacted this investigation when the very data points you're putting there -- actually, action has been taken against those individuals?

ROONEY: As an American citizen, I'm nervous and discontent that people would have those kinds of lack of impartiality and bad animus as displayed in those emails that they would have gone so far as to try to use that -- possibly use that dossier to discredit the campaign, I think that's going beyond just having political views.

KEILAR: Why if there is no evidence that this has infiltrated this investigation would you be calling for a purge, which is a word that, you know, an action that is more closely associated with authoritarian governments than democratic ones like the one you're a part of?

ROONEY: I think if you have 2 percent bad apples like this Strzok guy and Ohr, I think it's incumbent to make sure you know who they all are --

KEILAR: Again, one removed, one demoted. One was removed, one was demoted.

ROONEY: He's demoted but he still has a lot of authority in the other job he has. And he still just lacks impartiality and is very aggressive in his views.

(END VIDEO CLIP)

LEMON: So let's discuss now. Rick Santorum is here with me, CNN senior political commentator and former Republican presidential candidate and a Pennsylvania senator as well. That's a big resume there.

And also Shawn Turner, CNN national security analyst and the former director of communications for U.S. national intelligence as well. Big resume as well.

So, gentlemen, welcome. Senator, you know, a member of your party calling for a purge at the FBI and the DOJ for a second time now. What's your reaction to that?

RICK SANTORUM, CNN SENIOR POLITICAL COMMENTATOR: Yes, well, I think a purge is in fact too strong of a word. I wouldn't use that term. But I think the general consensus among Republicans is there is concern about impartiality with respect to this investigation, impartiality with respect to the behavior of the FBI before the election. And there is a call, I think, not just folks looking for a purge, but looking for answers to have some sort of investigation of the FBI, to look into, you know, whether that did have some impact on either the election or on this investigation.

LEMON: From text messages from two people?

SANTORUM: Well, as you know, I mean, the person we are talking about here was a very key figure in this investigation. Both the investigation, the original investigation and the Trump dossier to Jim Comey's activities prior to the election, as well as in the investigation afterwards. So, it's not just some one person. It's one very key and central figure. And one that needs to be investigated.

LEMON: But one as my colleague Brianna Keilar kept pointing out is no longer part of this investigation?

SANTORUM: Doesn't mean that the activities prior to shouldn't be investigated. I think it was correct that Director Mueller did remove him from the investigation. But that doesn't mean that we can't look or shouldn't look into what happened prior to that.

LEMON: Shawn, does this look like another piece of a coordinated effort to undermine the U.S. intelligence?

SHAWN TURNER, CNN NATIONAL SECURITY ANALYST: You know, it does concern me that once again we are kind of questioning the motives of people in the intelligence community. You know, Don, look, we need to absolutely kind of dispel with this false claim or false suggestion that people in government who have political views that line up with the left or the right are somehow incapable of doing their job in a non-biased fashion.

Now, obviously we had a couple of individuals who violated that trust by sending text messages. But, look, I spent more than two decades serving in government, in national security and intelligence.

[14:05:01] And I can tell you from experience that when you're concerned with the business of protecting this country and protecting our democratic institutions, and you understand that as people in the FBI do, you understand that if you fail or if your agency fails, that you're going to be blamed, the last thing you are thinking about is what's best for Democrats and Republicans.

So, I think that we need to take a step back and look at it for what it is. We had a couple of individuals who crossed the line, they were dealt with as they should be dealt with, but that in should in no way kind of besmirched the reputation of the entire intelligence community or the FBI.

(CROSSTALK)

SANTORUM: I would agree that it shouldn't (INAUDIBLE) of the entire community, This doesn't mean the person they did in the position he had, where he was clear, he wanted to stop Donald Trump from being elected. So, you know, the idea that we shouldn't question people in the intelligence community or FBI, well, what person is beyond question?

I mean, Shawn, with all due respect, we do need to question people who are out of line.

TURNER: A purge is not focused on a couple of individuals. We had a congressman --

SANTORUM: Agreed.

TURNER: -- who acknowledges that he comes from a world of business so he may not have the advantage of full knowledge when it comes to understanding the commitment and dedication of people in government. But a purge is focused on the entire agency, and it's too far.

SANTORUM: I agree.

TURNER: You identify the individuals and deal with them, and that's what Mueller has done.

LEMON: Senator, let me ask you this. So, the House and Senate are both doing investigations, right?

SANTORUM: Yes.

LEMON: And they are both, everyone there has a political leaning. Do you think they can't conduct fair investigations when they will tell you they are Democrat or a Republican? Do you think they would hand their cell phones over to let people look at text messages between them and another colleague? Do you think that would be fair?

SANTORUM: I think it's different when you are in the political context. The answer is I would hope that the House and Senate can conduct fair investigations. But I don't think anybody questions that if you are a Democrat, you are going to look a lot harder at Republicans and vice-versa. That politics doesn't enter into it. And shouldn't, no, probably shouldn't. But does it? Well, yes, of course it does so some degree.

But the evidence will lead ultimately where the evidence leads. But as you know, you have majority and minority reports, and why? Because they look at the evidence and they spin it or they see differently. That shouldn't come to the case when it comes to our -- to the people who are really assigned to do these nonpartisan, you know, investigations.

LEMON: Do you say something in text message that you wouldn't say in a public place?

SANTORUM: Yes, but again, you are talking about someone who is responsible.

(CROSSTALK)

LEMON: I'm not saying they will carry that in their personal life. I say things with my friends that I would not say on television. I say things with my family that I wouldn't say on television. I say things with my friends on text that I would dare say on television. It doesn't mean that's my view, sometimes I'm just having a conversation with people. It doesn't mean that I'm bias. It doesn't mean that you are bias.

SANTORUM: It's different when you are musing whether someone is fit for office or not.

LEMON: This is before they were part of the investigation. This was during the election.

SANTORUM: Doesn't matter. I mean, he was involved with the dossier. He was involved with a whole bunch of things looking into the election that Director Comey was involved with. So, it was involved with that. And he was expressing opinions about the fitness of at that time candidate Trump for office.

No, I think those are legitimate reasons.

(CROSSTALK)

LEMON: Did you read the specific messages? Because the specific messages were to incidents that the president has done, like commenting on genital size. He thought it was inappropriate. Did you think it was appropriate for the candidate to be commenting on genital size on the national stage? That was one of the text messages.

SANTORUM: Obviously. No. But there were other text messages, you know, that went more to the heart of --

(CROSSTALK)

LEMON: Do you support the president of the United States? Do you support this president?

SANTORUM: I do support the president.

(CROSSTALK)

LEMON: But you thought it was inappropriate for him to make that comment. So what is wrong with someone saying that in the text message?

SANTORUM: Again, I'm not the person charged with the responsibility of doing nonpartisan investigation about whether this person was conducting activities that were criminal in nature.

LEMON: Yes.

TURNER: And, Don, I think it's important to point out the person that was charged with that behavior has been dealt with.

And I just -- you know, the question here is what else do we want Bob Mueller to do? He did the right thing. When he was presented with information that he had someone on his team who was not behaving inappropriate manner, he dealt with that individual in a way that any of us would have dealt with an individual who was not performing as he should.

So, at this point, everything else that we are kind of talking about now suggests that because he dealt with that situation, because it's past, that there must necessarily be something else that he needs to deal with and no evidence to support that.

SANTORUM: If you are looking for a suggestion what Bob Mueller could do, there are I think 15 attorneys on the case, and the vast majority of them have actually fairly clear records of alliances with the Democratic Party, number one.

[14:10:05] Number two, there are a couple of them very high profile in their aggressiveness toward Republicans and conservatives.

So, I mean, if you want -- if you wanted an investigation that was going to be accepted in a bipartisan way, then you wouldn't go out and pick people that have clear records of affiliation with one side or the other.

LEMON: Nine of the attorneys why Democratic donors. It's not vast majority of people who are on the investigation.

SANTORUM: Nine of the 15 attorneys.

LEMON: They're not all attorneys who are on the team as well. There are investigators and there are other people as well. Nine of 15 of the attorneys. So, attorneys take oaths as well to abide by the law and to be nonpartisan.

SANTORUM: I understand. But you can't separate yourself and what you believe from the investigation. Very hard to do that. You come in with a certain point of view.

Let's just, this idea that you can compartmentalize everything, fine, then why don't you compartmentalize and have someone who have a different point of view. But when you see all on sort of one point of view, you have a legitimate reason to question if the majority of people that have been appointed as staff attorneys are of one particular ilk or one particular point of view, you maybe wander whether there is a sense of -- Bob Mueller to try to have impartial investigation of the facts.

TURNER: You know, Don, by that logic we have to take a step back and take a look at every sitting judge in this country, because, look, we have all political leanings one way or the other. So the underlying idea here is that you can simply not step into a role and do your job in way that's impartial and unbiased, then there is no area of government where people have to make judgments that's safe. I mean, look, the idea here is you bring people together who may have different views, but that those people can leave those views at the door, and they can go in and they can do their job.

And I can tell you that people in government, look, we are a reflection of society, so there are people in government who struggle to do that sometimes. But the vast majority of people understand that the mission that you have is so big, so significant, so important, that when you allow political views to come into that mission, then you putting this country at risk and you're putting a lot of things that matter to the American people.

LEMON: I'm out of time.

SANTORUM: I couldn't agree. One final point, Don. I agree with everything you just said, Shawn. But don't you have someone on the other side? If everyone is identified with one particular point of view --

LEMON: I'm being told the vast majority of the FBI are conservatives, Rick.

SANTORUM: Well, I'm not talking about this investigation and those who are leading. I'm not talking about the FBI. I'm talking about this investigation.

LEMON: Thank you very much. Both of you, I appreciate it.

TURNER: Thanks.

SANTORUM: Thank you.

LEMON: Shawn Turner and Rick Santorum.

Up next, President Obama says it's his first interview since leaving the White House. Others are calling it, "When Harry Met Barry." Former President Barack Obama sits down with Prince Harry. Among the topics up for discussion, the use of social media by people in power, and, of course, will Trump or Obama be invited to the royal wedding?

And this just in, I should say, President Trump returning to the golf course again today, only would only never know it if you, you know, from this view, because it is, you can see it right there, there's an unmarked white truck sort of blocking the way, attempting to block our cameras on the public property, showing what the president was doing today. More on this video coming up.

(COMMERCIAL BREAK)

[14:17:10] LEMON: President Obama is opening up about his life after the White House, in a one-on-one interview with his pal, the newly engaged Prince Harry. This was Obama's first interview since leaving office. Prince Harry met with Obama in September but the interview just aired today on the BBC.

Obama talked about having more time on his hands, but he also appreciated about how leaders should use social media responsibly.

(BEGIN VIDEO CLIP)

BARACK OBAMA, FORMER PRESIDENT: The question I think really has to do with how do we harness this technology in a way that allows a multiplicity of voices, allows a diversity of views, but doesn't lead to a balkanization of our society, but rather continues to promote ways of finding common ground.

And I'm not sure government can legislate that. But what I do believe is that all of us in leadership have to find ways in which we can recreate a common space on the Internet. One of the dangers of the Internet is that people can have entirely different realities. They can be just cocooned in information that reinforces their current biases.

(END VIDEO CLIP)

LEMON: What a difference a year makes, right?

Now with me is Rebecca Berg, CNN political reporter, and Amie Parnes, CNN political analyst and senior political correspondent for "The Hill".

So listen, Amie, I'm going to start with you first. The former president never mentions Donald Trump by name.

AMIE PARNES, CNN POLITICAL ANALYST: Yes.

LEMON: But do you have is there any doubt who he's talking about? Is it a veiled reference?

PARNES: It's a veiled reference and this is something he did throughout his presidency. I covered him when he was up against Mitt Romney. You never heard him really jab Mitt Romney until it really mattered towards the very end. But it was always very -- he kept it kind of close held and he wasn't taking a clear jab, he was, everyone knew he was, but he was very polite about it.

LEMON: Rebecca, do you think everyone knows who he's talking about? Do you believe he's talking about the current president?

REBECCA BERG, CNN POLITICAL REPORTER: You know, Don, what actually surprised me more than potentially these veiled jabs at President Trump, which you can interpret it either way, I think, was that President Obama had multiple opportunities in this interview to take direct jabs at President Trump. For example, Prince Harry asked him about inauguration day, how he was feeling at that moment, and some other issues as well, and President Obama didn't bite and take that bait. I think that was deliberate attempt on his part to sort of stay above the fray.

And we've seen this from him in his post-presidency in general. He's trying not to engage on President Trump and trying to really focus on the big issues that he's going to be focusing his attention and his energy on in terms of shaping policy and moving forward.

LEMON: When I said what a difference a year makes, I mean, the styles couldn't be more different for the current president and the former president.

[14:20:06] They also -- the two men also got a bit of time to work in a rapid fire Q&A. Watch this.

(BEGIN VIDEO CLIP)

PRINCE HARRY: Harry or William?

OBAMA: William right now.

PRINCE HARRY: "Titanic" or "The Bodyguard"?

OBAMA: "Titanic".

PRINCE HARRY: "Suits" or "The Good Wife"?

OBAMA: "Suits", obviously.

PRINCE HARRY: Great. Great answer. Cigarettes or gum?

OBAMA: Gum now, baby.

PRINCE HARRY: White House or Buckingham Palace?

OBAMA: White House just because Buckingham Palace looks like that would take a really long time to mow.

PRINCE HARRY: OK, fair enough.

OBAMA: A lot of upkeep.

PRINCE HARRY: Queen or The Queen?

OBAMA: The queen. (END VIDEO CLIP)

LEMON: Of course he had to say the queen, Rebecca. What do you think of those answers?

BERG: Of course. I mean, it was fun they both agreed "Suits" is better show than "The Good Wife". Of course, the show that Meghan Markle, Prince Harry's fiancee appeared on until recently, or is still appearing until she takes on her role in the royal family.

Just some very fun light-hearted answers. And you can see there have been reports they have developed a friendship, Prince Harry and the Obamas. And you can see that sort of in their rapport that they share very fun, very light-hearted.

LEMON: Amie, which leads me to the next question which president if any of the two would get invited to Harry's wedding?

PARNES: Well, I think Rebecca is right. They do have a rapport, they have a friendship. President Obama goes kind of way back with this family. He went in. He had this little meeting with Prince William and Kate and he's met the queen. And so, I think he and Harry get along very well.

So I think he might score an invite. I would think he would.

LEMON: Yes. But he later deflected -- when ask if he would invited the president to his wedding, he sort of deflected and said we haven't decided, that that was pretty strategic and diplomatic, don't you think?

PARNES: Oh, yes.

LEMON: Pushing it off.

PARNES: Definitely. And something President Obama did as well. You know, he wasn't going after President Trump. He was keeping it very kind of -- you know, very polite, very political, if you will. Something that we're not seeing from the current president.

LEMON: We have that moment, I didn't realize it. Let's play it and then we'll talk about it more.

(BEGIN VIDEO CLIP)

PRINCE HARRY: We share the same kind of mindset outlook on the charitable sector, on foundations, and mainly on the youth of today, young people of this world are incredibly inspirational.

REPORTER: Well enough to invite him to your wedding?

PRINCE HARRY: I don't know about that. That's some -- we haven't put the invites all the guest list together yet. So, who knows whether he'll be invited or not. Wouldn't want to run that surprise.

(END VIDEO CLIP) LEMON: Rebecca, that was -- he was pretty quick on his feet. I mean, he did -- Harry interviewed Obama before he got engaged, I think they did it back in September, but it just aired on BBC Radio.

BERG: Right. Well, certainly he wouldn't want to create an international incident within weeks of getting engaged. But you have to wonder what the Trump tweet would look like if President Obama and Michelle Obama were invited and the president was not. I could imagine it being something like the president's tweets about Time Person of the Year, you know, I wouldn't want to be invited, and I wouldn't want to attend, something like that.

LEMON: Yes.

BERG: We'll see.

LEMON: Thank you both.

PARNES: Thank you.

LEMON: Good to see both of you.

BERG: Thanks, Don.

LEMON: Rebecca Berg and Amie Parnes.

Up next, can President Trump build bridges with Democrats? After a politically divided year, is bipartisan a possibility in 2018?

Also with the New Year just days away, why thousands of homeless are scrambling, homeowners I should say, homeowners are scrambling before the new law -- tax law goes into effect? We'll tell you why back in a moment.

(COMMERCIAL BREAK)

[14:27:50] LEMON: The president has a -- the president has a mighty ambitious New Year's goal: building bridges with Democrats. You heard me. President Trump wants to work with Democrats on a bipartisan bill to repair the nation's aging infrastructure, by renovating highways, rebuilding bridges and shoring up crumbling tunnels.

Well, as a candidate, Trump promised to introduce $1 trillion infrastructure plan within 100 days of moving into the White House. That did not happen. And the president was not exactly buddy-buddy with Dems during his first year in office.

Let's talk about it now with CNN politics reporter Dan Merica.

Dan, hello to you. What are Trump's biggest obstacles in this new push for a bipartisan infrastructure deal?

DAN MERICA, CNN POLITICS REPORTER: Hey, Don. The biggest issues are the structure of what he's going to propose and the politics of Trump. The structure is something Democrats haven't gotten behind in the past. What President Trump wants to do, rolling this out in January, according to his aides, is spend about $200 billion on an infrastructure plan that they hope will incentivize another $800 billion of state and local money to fund some of those infrastructure projects.

Democrats have been more in favor of a larger federal funding effort. Obviously, President Trump supported a $1 trillion infrastructure plan during his campaign. That hasn't really come to fruition yet.

The bigger issue is the politics of Trump. Right now, President Trump is historically unpopular for a president in his first year, and that makes it unlikely that Democrats are going to get behind him and give him a win. This is increasingly an issue during midterm years. Many Democrats will be up for reelection in 2018, including in states that President Trump won. It's unlikely with the president so unpopular that they're going to go along with this infrastructure plan because it's difficult for them politically.

The base of the Democratic Party is very against Trump right now. And that means that any Democrat running for re-election this year is going to have to do the same, Don.

LEMON: So, Dan, you are in West Palm Beach. You're traveling with the president. I understand he played another round of golf today. CNN got video of the president playing golf for the last few days.

But I understand something different happened today. What was it?

MERICA: You know, our job down here is to cover the president, to tell our viewers what he is doing on a daily basis. Over the last few days, we've gotten video of the president golfing at his nearby golf club here in West Palm Beach.